Big Question - King Lear

In King Lear, we see characters both fail and thrive when faced with difficult situations. Lear himself dies at the end of the pain because he is so overcome with grief and hardship over the deaths of his daughters that he can no longer push himself to live. Edgar, however, is able to survive through the death of his father and killing his own brother to eventually become King. Both Lear and Edgar fostered anger towards the parties who died (Regan, Goneril, Cordelia, Gloucester, and Edmund respectively) but Edgar was able to overcome the tragedy while Lear could not hold on. What could have brought upon these two very different outcomes from these characters? Did he harbor a deeper hatred for the one who had wronged him? Or was Edgar's will to endure simply stronger than Lear's?